Apparatus, system, and method of controlling display of image data, and recording medium

ABSTRACT

A display control apparatus capable of controlling display of images on a first display, obtains display area information indicating a size of a display area of the first display for displaying a second image generated at an external apparatus, transmits to the external apparatus resolution information indicating a resolution of image data that matches the size of the display area of the first display, receives from the external apparatus second image data having the resolution that matches the size of the display area of the first display, the second image data being generated at the external apparatus based on the second image, and controls the first display to display the second image in the display area based on the second image data received from the external apparatus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is based on and claims priority pursuant to 35U.S.C. §119(a) to Japanese Patent Application No. 2015-191005, filed onSep. 29, 2015, in the Japan Patent Office, the entire disclosure ofwhich is hereby incorporated by reference herein.

BACKGROUND

Technical Field

The present invention relates to an apparatus, system, and method ofcontrolling display of image data, and a recording medium.

Discussion of the Background Art

With the need for reducing costs or times associated with businesstrips, communication systems are widely used, which are capable ofcarrying out videoconferences among remotely located sites through acommunication network such as the Internet. In such communicationsystems, image data and audio data are transmitted or received among aplurality of communication terminals. As image data for transmission, inaddition to image data of a captured image that is captured at thecommunication terminal, image data of an input image that is input froman external apparatus to the communication terminal may be transmittedto the counterpart communication terminal.

When displaying the input image input from the external apparatus on adisplay provided for the communication terminal, the input image may notbe appropriately displayed at a right place with a right size.

SUMMARY

Example embodiments of the present invention include a display controlapparatus, which controls display of images on a first display providedfor the display control apparatus, the images including a first imagegenerated at the display control apparatus and a second image generatedat an external apparatus. The display control apparatus obtains displayarea information indicating a size of a display area of the firstdisplay for displaying the second image, transmits to the externalapparatus resolution information indicating a resolution of image datathat matches the size of the display area of the first display, andreceives from the external apparatus second image data having theresolution that matches the size of the display area of the firstdisplay, the second image data being generated at the external apparatusbased on the second image. The display control apparatus controls thefirst display to display the second image in the display area based onthe second image data received from the external apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the embodiments and many of theattendant advantages and features thereof can be readily obtained andunderstood from the following detailed description with reference to theaccompanying drawings, wherein:

FIG. 1 is a schematic diagram illustrating a communication systemaccording to an embodiment of the present invention;

FIG. 2 is an illustration for explaining a communication state among aplurality of communication terminals in the communication system of FIG.1;

FIG. 3 is an external view illustrating a communication terminal of thecommunication system of FIG. 1;

FIG. 4 is a schematic block diagram illustrating a hardwareconfiguration of the communication terminal of FIG. 3;

FIG. 5 is a schematic block diagram illustrating a hardwareconfiguration of an external input apparatus, a communication managementsystem, and a relay device of the communication system of FIG. 1;

FIG. 6 is a schematic block diagram illustrating a functionalconfiguration of the communication terminal, the external inputapparatus, and the communication management system of the communicationsystem of FIG. 1;

FIG. 7A is an illustration of an example data structure of a layoutmanagement table; FIG. 7B is an illustration of an example screendisplaying an image; FIG. 7C is an illustration of an example screendisplaying an image, when receiving a request for changing a size of adisplay area for displaying an image;

FIG. 8 is an illustration of an example data structure of anauthentication management table;

FIG. 9 is a data sequence diagram illustrating operation of preparingfor starting communication between terminals, performed by thecommunication system of FIG. 1, according to an embodiment;

FIG. 10 is a data sequence diagram illustrating operation of installingan input image control program onto an input apparatus, according to anembodiment;

FIG. 11 is a data sequence diagram illustrating operation of convertingresolution of display data, performed by the communication system ofFIG. 1, according to an embodiment;

FIG. 12 is a flowchart illustrating operation of converting resolutionof display data, performed by the external input apparatus, according toan embodiment; and

FIG. 13 is a data sequence diagram illustrating operation of changing asize of a display area for displaying display data, performed by theterminal, according to an embodiment.

The accompanying drawings are intended to depict embodiments of thepresent invention and should not be interpreted to limit the scopethereof. The accompanying drawings are not to be considered as drawn toscale unless explicitly noted.

DETAILED DESCRIPTION

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentinvention. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise.

In describing embodiments illustrated in the drawings, specificterminology is employed for the sake of clarity. However, the disclosureof this specification is not intended to be limited to the specificterminology so selected and it is to be understood that each specificelement includes all technical equivalents that have a similar function,operate in a similar manner, and achieve a similar result.

Referring to the drawings, embodiments of the present invention aredescribed.

FIG. 1 is an overall configuration diagram of a communication system 1according to an embodiment of the present invention. As illustrated inFIG. 1, the communication system 1 includes a plurality of communicationterminals (10 aa, 10 ab, . . . ), a relay device 30, and a communicationmanagement system 50. The communication system 1 controls communicationof content data, such as image data and audio data, to carry outvideoconference among a plurality of remotely located sites. Examples ofimage data include, but not limited to, data of a captured imagecaptured at the communication terminal (10 aa, 10 ab, . . . ), and dataof input image input to the communication terminal (10 aa, 10 ab, . . .).

The communication terminals (10 aa, 10 ab, . . . ), the relay device 30,and the communication management system 50 are connected to one anotherthrough a communication network 2 to be communicable with one another.

In the following, a “communication terminal” may simply be referred toas a “terminal”, and a “communication management system” may simply bereferred to as a “management system”. In this disclosure, an arbitraryone or ones of the plurality of terminals (10 aa, 10 ab, . . . ) is/arerepresented as a “terminal(s) 10”.

In this example, the communication network 2 is implemented mainly bythe Internet. The communication network 2 may not only include a wirednetwork, but also a wireless network such as a network in compliancewith WiFi (Wireless Fidelity) or Bluetooth.

Note that the communication terminal may be used not only forcommunication between different offices or for communication betweendifferent rooms in the same office, but also for communication withinthe same room or for outdoor-indoor communication or outdoor-outdoorcommunication. In the case where the terminal 10 is used outside,wireless communication using a mobile phone communication network or thelike is performed.

The terminal 10 illustrated in FIG. 1 may be implemented by avideoconference terminal capable of carrying out communication by a userthrough transmission or reception of content data. More specifically,the terminal 10 transmits or receives content data using a predeterminedcommunications protocol. The communications protocol used by theterminal 10 is mainly defined by a call control protocol used forconnecting or disconnecting connections with the counterpart terminal,and an encoding format used for encoding the contents data to an IPpacket.

Examples of the call control protocol being used by the terminal 10include, but not limited to, (1) session initial protocol (SIP), (2)H.323, (3) the extended SIP, (4) Instant Messenger (IM) Protocol such asextensible messaging and presence protocol (XMPP), ICQ (RegisteredTrademark), AIM (Registered Trademark), or Skype (Registered Trademark),(5) protocol using the SIP message method, (6) Internet relay chat (IRC)protocol, and (7) extended IM based protocol such as Jingle.

The relay device 30, which may be implemented by one or more computers,relays content data among the plurality of terminals 10. The managementsystem 50, which may be implemented by one or more computers, centrallymanages login authentication of the terminal 10, a communication stateof the terminal 10, a contact list, and a communication state of therelay device 30. The image data may be a video image or a still image,or both of the video image and the still image.

FIG. 2 illustrates an example case in which a plurality of terminalscommunicate with one another. In the communication system 1 referring toFIG. 2, the management system 50 establishes a management datacommunication session “sei” with each one of the terminals 10, totransmit or receive various management data between the terminals 10.

The terminal 10 establishes a content data communication session “sed”with the relay device 30, to transmit or receive image data and audiodata, in the H.264/SVC standard.

One of the terminals 10 illustrated in FIG. 2 is connected to an inputapparatus 40 through, for example, a network. The input apparatus 40 isprovided separately from the terminal 10 and inputs image data to theconnected terminal 10. The terminal 10, which receives the input imagedata, transmits the input image data with the captured image data thatis captured at the terminal 10, to the counterpart terminal 10.

<Hardware Configuration of Communication System>

Now, a hardware configuration of the communication system 1 isdescribed. FIG. 3 is a perspective view illustrating an externalappearance of the terminal 10 according to the embodiment. Asillustrated in FIG. 3, the terminal 10 includes a casing 1100, an arm120, and a camera housing 1300. The casing 1100 includes a front sidewall 1100 having a plurality of air intake holes formed over the nearlyentire surface of the intake surface, and a back side wall 1120 having aplurality of exhaust holes over the nearly entire surface of the exhaustsurface 1121. As a cooling fan included in the casing 1100 is driven,air behind the communication terminal 10 can be taken in via the inletface and exhausted to the rear of the communication terminal 10 via theexhaust face 1121. A right-side wall 1130 of the casing 1100 has a soundpickup hole 1131 formed thereon, and a built-in microphone 114,described later, is capable of picking up sound such as sound, noise, orvibration.

The casing 1100 has an operation panel 1150, which is provided at afront surface toward the right side wall 1130. The operation panel 1150includes a plurality of operation keys 108 a to 108 e, a power switch109, and a plurality of sound output holes 1151. Through the soundoutput holes 1151, a speaker 115 of the terminal 10 is able to outputsounds such as sounds generated based on human voice. The casing 1100further includes a holder 1160, which is provided at the front surfacetoward the left side wall 1140. The holder 1160, which has a concaveshape, accommodates therein the arm 1200 and the camera housing 1300.The right side wall 1130 is further provided with a plurality ofconnection ports 1132 a to 1132 c (“connection ports 1132”). Theconnection ports 1132 allow electrical connection to an external devicethrough an external device connection I/F 118. The casing 1100 furtherincludes a left side wall 1140, which is provided with a connection portto connect the external display 120 to the display I/F 117 through acable 120 c.

The following description uses the term “operation key(s) 108” forindicating an arbitrary one or ones of the operation keys (108 a to 108e), and the term “connection port(s) 1132” for indicating an arbitraryone or ones of the connection ports (1132 a to 1132 c).

The arm 1200 is attached to the casing 1100 via a torque hinge 1210 soas to be rotatable in the vertical direction within the range of a tiltangle θ1 of 135 degrees with respect to the casing 1100. FIG. 3illustrates the case where the tilt angle θ1 is 90 degrees. The camerahousing 1300 has a built-in camera 112 provided thereon, which will bedescribed later, and the camera 112 can capture an image of a user, adocument, a room, or the like. The camera housing 1300 is formed with atorque hinge 1310. The camera housing 1300 is attached to the arm 1200through the torque hinge 1310. The camera housing 1300 is attached tothe arm 1200 via the torque hinge 1310 so as to be rotatable in thevertical and horizontal directions within the range of a pan angle θ2 of±180 degrees and a tilt angle θ3 of ±45 degrees with respect to the arm1200, in which the state illustrated in FIG. 3 serves as 0 degrees.

Since the relay device 30, the input apparatus 40, and the managementsystem 50 each have the same appearance as that of a general computer, adescription of the appearance thereof is omitted.

FIG. 4 is a schematic block diagram illustrating a hardwareconfiguration of the communication terminal 10. As illustrated in FIG.4, the communication terminal 10 of the embodiment includes a centralprocessing unit (CPU) 101 that controls entire operation of thecommunication terminal 10, a read only memory (ROM) 102 that stores aprogram for operating the CPU 101 such as an initial program loader(IPL), a random access memory (RAM) 103 that operates as a work area forthe CPU 101, a flash memory 104 that stores various types of data, suchas the terminal control program, image data, and audio data, a solidstate drive (SSD) 105 that controls reading/writing of various types ofdata from/to the flash memory 104 under control of the CPU 101, a medium1/F 107 that controls reading/writing (storage) of data from/to arecording medium 106, the operation key 108 operated in the case of, forexample, selecting a counterpart terminal of the communication terminal10, the power switch 109 for turning on/off the power of thecommunication terminal 10, and a network interface (I/F) 111 fortransmitting data using the communication network 2.

The terminal 10 further includes the built-in camera 112 that capturesan image of a subject and obtains image data under control of the CPU101, an imaging element I/F 113 that controls driving of the camera 112,the built-in microphone 114 that receives an audio input, the built-inspeaker 115 that outputs sounds, an audio input/output I/F 116 thatprocesses inputting/outputting of an audio signal between the microphone114 and the speaker 115 under control of the CPU 101, a display I/F 117that transmits image data to an external display 120 under control ofthe CPU 101, the external device connection I/F 118 for connectingvarious external devices, an alarm lamp 119 for notifying of an error infunctionality of the terminal 10, and a bus line 110 such as an addressbus and a data bus for electrically connecting the above-describedelements as illustrated in FIG. 4.

The display 120 is a display formed of liquid crystal or organicelectroluminescence (EL) that displays an image of a subject, anoperation icon, or the like. The display 120 is connected to the displayI/F 117 by the cable 120 c. The cable 120 c may be an analog red greenblue (RGB) (video graphic array (VGA)) signal cable, a component videocable, a high-definition multimedia interface (HDMI) signal cable, or adigital video interactive (DVI) signal cable.

The camera 112 includes a lens and a solid-state imaging element thatconverts an image (video) of a subject to electronic data throughphotoelectric conversion. As the solid-state imaging element, forexample, a complementary metal-oxide-semiconductor (CMOS) or acharge-coupled device (CCD) is used.

The external device connection I/F 118 is capable of connecting anexternal device such as an external camera, an external microphone, oran external speaker by using a Universal Serial Bus (USB) cable that isinserted into the connection port 1132 or the like. In the case where anexternal camera is connected, the external camera is driven inpreference to the built-in camera 112 under control of the CPU 101.Similarly, in the case where an external microphone is connected or anexternal speaker is connected, the external microphone or the externalspeaker is driven in preference to the built-in microphone 114 or thebuilt-in speaker 115 under control of the CPU 101.

The recording medium 106 is removable from the communication terminal10. The recording medium 106 can be any non-volatile memory that readsor writes data under control of the CPU 101, such that any memory suchas an electrically erasable and programmable read-only memory (EEPROM)may be used instead of the flash memory 104.

FIG. 5 is a schematic block diagram illustrating a hardwareconfiguration of the input apparatus 40, the communication managementsystem 50, and the relay device 30 of the communication system 1,according to the embodiment. The management system 50 includes a CPU 201that controls entire operation of the management system 50, a ROM 202that stores a program used for driving the CPU 201 such as an IPL, a RAM203 used as a work area for the CPU 201, the HD 204 that stores varioustypes of data such as the communication management program, a hard diskdrive (HDD) 205 that controls reading/writing of various types of datafrom/to the HD 204 under control of the CPU 201, a medium drive 207 thatcontrols reading/writing (storage) of data from/to a recording medium206 such as a flash memory, a display 208 that displays various types ofinformation such as a cursor, a menu, a window, characters, or an image,a network I/F 209 for transmitting data using the communication network2, a keyboard 211 including a plurality of keys for entering characters,numerals, and various instructions, a mouse 212 that selects andexecutes various instructions such as selection of a processing targetor movement of the cursor, a compact disc read-only memory (CD-ROM)drive 214 that controls reading/writing of various types of data from/toa CD-ROM 213 serving as an example of a removable recording medium, anda bus line 210 such as an address bus and a data bus for electricallyconnecting the above-described elements.

Since the relay device 30 and the input apparatus 40 each have ahardware configuration that is the same as or similar to that of theabove-described management system 50, descriptions thereof are omitted.While the hardware is substantially the same, a control program storedin the HD 204 differs among the relay device 30, the input apparatus 40,and the management system 50.

Note that the control program for the communication terminal 10, thecontrol program for the relay device 30, the control program for theinput apparatus 40, and the control program for management system 50 mayeach be recorded in a file in a format installable or executable on acomputer-readable recording medium for distribution. Examples of suchrecording medium include, but not limited to, compact disc-recordable(CD-R), digital versatile disc (DVD), and blue-ray disc.

<Functional Configuration of Communication System>

Now, a functional configuration of the communication system 1 isexplained. FIG. 6 is a schematic block diagram illustrating a functionalconfiguration of the terminal 10, the input apparatus 40, and themanagement system 50 in the communication system 1, according to theembodiment of the present invention. In FIG. 6, the terminal 10 and themanagement system 50 are connected through the communication network 2to transmit or receive data. The terminal 10 and the input apparatus 40are connected to transmit or receive data.

<Functional Configuration of Terminal>

The terminal 10 includes a transmitter/receiver 11, an operation input12, a login request 13, an image capturer 14, an audio input/output 15,a display control 16, a layout data obtainer 17, an external datatransmitter/receiver 18, and a memory control 19. These units arefunctions that are implemented by or that are caused to function byoperating any of the hardware components illustrated in FIG. 4 incooperation with the instructions of the CPU 101 according to theterminal control program expanded from the flash memory 104 to the RAM103. The terminal 10 further includes a memory 1000 configured by theRAM 103 and the flash memory 104.

(Layout Management Table)

FIG. 7A is an illustration of an example data structure of a layoutmanagement table. The memory 1000 stores a layout management DB 1001,such as the layout management table of FIG. 7A. The layout managementtable of FIG. 7A stores, for each type of image data to be outputthrough the display 120, an image data type, a priority in displayingthe image data with such image data type, position informationindicating a position at which such image data is displayed, and sizeinformation indicating a size of a display area of such image data. Thepriority is assigned to each image data type, such that, in displayingimage data with more than one type, the image data having an image datatype with a high priority (the small in number) is laid above the imagedata having an image data type with a low priority (the high in number).The position information indicates a position at which the image data isdisplayed on a screen. The position information in the layout managementtable defines the coordinate of the upper left corner of the displayedimage in percentage. The value of percentage is defined such that thecoordinate of the upper left corner of the display 120 corresponds to(0%, 0%), and the coordinate of the lower right corner of the display120 corresponds to (100%, 100%). Further, in the table of FIG. 7A, theupper left corner of the displayed image is defined by the leftcoordinate and the top coordinate. The size information indicates ahorizontal length and a vertical length of the display area fordisplaying the image data. The length may be expressed in number ofpixels.

FIG. 7B illustrates an example image that is displayed according toinformation stored in the layout management table of FIG. 7A. Morespecifically, the layout management table of FIG. 7A indicates that thecaptured image transmitted from the counterpart terminal is assignedwith the priority level “2”, and the display image (input image) inputfrom the input apparatus 40 is assigned with the priority level “1”. Thelayout management table of FIG. 7A further includes the positioninformation indicating that the captured image has the upper left corner(0, 0), and the size information indicating that the captured image hasa size of (1920, 1080). That is, the captured image of 1920 pixels by1080 pixels is displayed, with the upper left corner being at theposition (0, 0). In case the display 120 has a resolution of (1920,1080), the captured image D2 is displayed on a full screen asillustrated in FIG. 7B. The layout management table of FIG. 7A furtherincludes the position information indicating that the display image(input image) has the upper left corner (0, 0), and the size informationindicating that the display image has a size of (640, 480). That is, thedisplay image of 640 pixels by 480 pixels is displayed, with the upperleft corner being at the position (0, 0). Referring to FIG. 7B, thedisplay image D1 is displayed at this position, over the captured imageD2.

FIG. 7C illustrates an example case of changing the display area fordisplaying the image on a screen of the display 120. As a size of thedisplay area changes, a size of the image to be displayed on the displayarea, which is managed with the layout management table of FIG. 7A, ischanged accordingly. For example, in response to an instruction forenlarging the display area of the display data D1, the size informationfor the display area D1 is changed in the layout management table.

The memory 1000 stores an input image control program 1400, which is acontrol program for the input apparatus 40. The input image controlprogram 1400 can be installed onto the input apparatus 40, as the inputapparatus 40 mounts on the memory 1000. The input image control program1400, when mounted, provides functions of a display data obtainer 1451,a display data transmitter 1452, and a resolution converter 1453. As theinput image control program 1400 is transmitted to and installed ontothe input apparatus 40, the input apparatus 40 deploys the input imagecontrol program 1400 for execution of these functions.

Referring to FIGS. 4 and 6, a functional configuration of the terminal10 is described according to the embodiment. In the followingdescription of the functional configuration of the terminal 10,relationships of the elements in FIG. 5 with the functionalconfiguration of the terminal 10 in FIG. 6 will also be described.

The transmitter/receiver 11 of the terminal 10, which may be implementedby the instructions of the CPU 101, and the network I/F 111, transmitsor receives various data (or information) to or from each terminal,device, or system.

The operation input 12, which may be implemented by the instructions ofthe CPU 101, the operation key 108, or the power switch 109, receivesvarious inputs from the user.

The login request 13 may be implemented by the instructions of the CPU101. For example, as the power is turned on, the login request 13controls the transmitter/receiver 11 to automatically transmit loginrequest information for requesting login, and a current IP address ofthe starting terminal 10, to the management system 50 through thecommunication network 2. In addition, when the user turns the powerswitch 109 from on to off, the transmitter/receiver 11 transmits to themanagement system 50 state information indicating that the power is tobe turned off, and then the operation input 12 completely turns off thepower. Accordingly, the management system 50 can detect that the powerof the terminal 10 is turned from on to off.

The image capturer 14, which is implemented by instructions from the CPU101 and by the camera 112 and the imaging element I/F 113, captures animage of a subject and outputs image data obtained by capturing theimage.

The audio input/output 15 is implemented by the instructions of the CPU101 illustrated in FIG. 4 and by the audio input/output I/F 116illustrated in FIG. 4. After the sound of the user is converted to anaudio signal by the microphone 114, the audio input/output 15 receivesaudio data according to this audio signal. The audio input/output 15further outputs the audio signal according to the audio data to thespeaker 115, and the speaker 115 outputs sound.

The display control 16, which may be implemented by the instructions ofthe CPU 101 and the display I/F 117, controls transmission of image datato the display 120.

The layout data obtainer 17, which may be implemented by theinstructions of the CPU 101, searches the layout management table (FIG.7A) to obtain various information such as the position information andthe size information of each image to be displayed.

The external information transmitter/receiver 18, which may beimplemented by the instructions of the CPU 101 and the external deviceconnection I/F 118, transmits or receives various information withrespect to the input apparatus 40.

The memory control 19, which may be implemented by the instructions ofthe CPU 101 and the SSD 105 illustrated in FIG. 4, stores various datain the memory 1000 or reads various data from the memory 1000. Thememory 1000 stores a terminal identification (ID) for identifying eachterminal 10, a password, and the like. Further, every time image dataand audio data are received in performing communication with acounterpart terminal, the memory 1000 overwrites the image data andaudio data. The display 120 displays an image based on image data beforebeing overwritten, and the speaker 115 outputs sound based on audio databefore being overwritten.

Note that a terminal ID and a later-described relay device ID in theembodiment are examples of identification information that is used touniquely identify a specific terminal 10 and a specific relay device 30,respectively, such that a language, a character(s), a symbol(s), orvarious marks are not limited to the above-described embodiment. Forexample, a combination of at least two of the above-mentioned language,character(s), symbol(s), and various marks may be used as a terminal IDor a relay device ID. The terminal ID is any information used foridentifying the terminal 10. For example, in case the terminal ID isassociated with account information such as a user account of a specificuser, the account information identifying a specific account may be usedas the terminal ID.

<Functional Configuration of Management System>

The management system 50 includes a transmitter/receiver 51, anauthenticator 52, and a memory control 59. These elements correspond toa plurality of functions of hardware elements in FIG. 5, which operateaccording to the instructions of the CPU 201 (FIG. 5) that are generatedaccording to the communication management program read from the RAM 203onto the HD 204. The management system 50 further includes a memory5000, which may be implemented by the HD 204.

(Authentication Management Table)

FIG. 9 is an illustration of an example data structure of anauthentication management table. The memory 5000 stores anauthentication management DB 5002, which may be implemented by theauthentication management table of FIG. 8. In the authenticationmanagement table, for each one of the terminals 10 managed by themanagement system 50, the terminal ID and the password are stored inassociation with each other. For example, the authentication managementtable illustrated in FIG. 8 indicates that the terminal ID of theterminal 10 aa is “01aa”, and the password of the terminal 10 aa is“aaaa”.

(Functional Configuration of Management System)

Next, referring back to FIG. 6, a functional configuration of themanagement system 50 will be described in detail. In the followingdescription of the functional configuration of the management system 50,relationships of the elements in FIG. 5 with the functionalconfiguration of the management system 50 in FIG. 6 is also described.

The transmitter/receiver 51, which may be implemented by theinstructions of the CPU 201 and the network I/F 209, transmits orreceives various data (or information) to or from each terminal, device,or system through the communication network 2.

The terminal authenticator 52, which is implemented by the instructionsof the CPU 201 illustrated in FIG. 5, performs terminal authenticationby searching the terminal information management DB 5002 of the memory5000 by using a terminal ID and a password included in login requestinformation received via the transmitter/receiver 51 as search keys anddetermining whether the same pair of a terminal ID and a password ismanaged in the terminal information management table (FIG. 8).

The memory control 59, which may be implemented by the instructions ofthe CPU 201 and the HDD 205, or the instructions of the CPU 201, storesvarious data in the memory 5000 or reads various data from the memory5000.

<Functional Configuration of Input Apparatus>

The input apparatus 40 includes a transmitter/receiver 41, a connectiondetector 42, an installation determiner 43 a, a program obtainer 43 b, aresolution obtainer 44, a display control 47, a mount unit 48, a displaydata obtainer 451, a display data transmitter 452, a resolutionconverter 453, and a memory control 49. These units are functions thatare implemented by or that are caused to function by operating any ofthe hardware components illustrated in FIG. 5 in cooperation with theinstructions of the CPU 201 according to the input apparatus controlprogram expanded from the HD 204 to the RAM 203. The input apparatus 40includes a memory 4000 configured by the HD 204 illustrated in FIG. 5.

The transmitter/receiver 41, which may be implemented by theinstructions of the CPU 201 and the network I/F 209, transmits orreceives various data (or information) to or from the terminal 10.

The connection detector 42, which may be implemented by the instructionsof the CPU 201 and the network I/F 209, detects a connection between theinput apparatus 40 and the terminal 10.

The installation determiner 43 a, which may be implemented by theinstructions of the CPU 201, determines whether the input apparatus 40is installed with the input image control program, such as the programthat operates as the display data obtainer 1451, display datatransmitter 1452, and resolution converter 1453.

The program obtainer 43 b, which may be implemented by the instructionsof the CPU 201, receives the input image control program from the memory1000 of the terminal 10, such as the program that operates as thedisplay data obtainer 1451, display data transmitter 1452, andresolution converter 1453.

The resolution obtainer 44, which may be implemented by the instructionsof the CPU 201, obtains a resolution of the display 208, and resolutioninformation indicating a resolution of a display area of the terminal10.

The display control 47, which may be implemented by the instructions ofthe CPU 201 in cooperation with the display 208, controls the display208 to display image data as display data.

The mount unit 48, which may be implemented by the instructions of theCPU 201, mounts the memory 1000 of the terminal 10 to cause the inputimage control program 1400 to be installed onto the input apparatus 40.

The display data obtainer 451, which may be implemented by theinstructions of the CPU 201, obtains image data being displayed on thedisplay 208, as display data.

The display data transmitter 452, which may be implemented by theinstructions of the CPU 201 and the network I/F 209, transmits imagedata to the terminal 10 for display.

The resolution converter 453, which may be implemented by theinstructions of the CPU 201, converts a resolution of display data to betransmitted to the terminal 10, based on a resolution of the display 208for the input apparatus 40 and a resolution of a display area of theterminal 10.

The memory control 49, which may be implemented by the instructions ofthe CPU 201 and the HDD 205, or the instructions of the CPU 201, storesvarious data in the memory 4000 or reads various data from the memory4000.

<Operation>

Now, operation of starting communication between the terminals 10 aa and10 da is described according to an embodiment. FIG. 9 is a data sequencediagram illustrating operation of starting communication between theterminals 10 aa and 10 da.

When the user of a starting terminal (terminal 10 aa) turns on the powerswitch 109 illustrated in FIG. 3, the operation input 12 illustrated inFIG. 6 accepts the power on operation and turns on the power (S21). Inresponse to acceptance of the power on operation, the login request 13automatically transmits login request information indicating a loginrequest from the transmitter/receiver 11 to the management system 50 viathe communication network 2 (S22). The login request informationincludes a terminal ID for identifying the terminal 10 aa, which is alocal terminal serving as the starting terminal, and a password. Theterminal ID and the password are data that have been read via the memorycontrol 19 from the memory 1000 and sent to the transmitter/receiver 11.In the case of transmitting login request information from the terminal10 aa to the management system 50, the management system 50, which is areceiving side, can obtain the IP address of the terminal 10 aa, whichmay be received from the terminal 10 aa with the login requestinformation.

Next, the authenticator 52 of the management system 50 performs terminalauthentication by searching the authentication management table (FIG. 8)of the memory 5000 by using the terminal ID and the password included inthe login request information received via the transmitter/receiver 51as search keys, and determining whether the same terminal ID and thesame password are managed in the authentication management table (S23).

The transmitter/receiver 51 of the management system 50 transmitsauthentication result information indicating an authentication resultobtained by the authenticator 52 to the starting terminal (terminal 10aa) which has sent the above-mentioned login request, via thecommunication network 2 (S25). In the embodiment, the case in which ithas been determined by the authenticator 52 that the terminal 10 aa is aterminal that has a legitimate use authority will be described asfollows. Further, in the following, it is assumed that the terminal 10da has logged in the management system 50 in a substantially similarmanner as described above referring to S21 to S25.

As the user at the terminal 10 aa presses the operation keys 108illustrated in FIG. 3 and selects the terminal 10 da as a counterpart,the operation input 12 illustrated in FIG. 6 accepts a request forstarting communication with the counterpart terminal 10 da (S41). Thetransmitter/receiver 11 of the starting terminal (terminal 10 aa)transmits, to the management system 50, start request information(communication start request) indicating a request for startingcommunication (S42). The communication start request includes theterminal ID “01aa” of the terminal 10 aa, and the terminal ID (“01da”)of the counterpart terminal (terminal 10 da).

The transmitter/receiver 51 of the management system 50 transmits thecommunication start request, to the terminal 10 da that is thecounterpart terminal for the terminal 10 da (S43). Thetransmitter/receiver 51 of the management system 50 transmits, to theterminal 10 da, relay device connection data to be used for connectingwith the relay device 30. The relay device connection data includes theIP address of the relay device 30, authentication information to be usedfor authentication such as the password, a port number, etc.

As the communication start request is received, the transmitter/receiver11 of the counterpart terminal 10 da transmits, to the management system50, start permission information (response) indicating to accept thecommunication start request in response to the communication startrequest (S44). The transmitter/receiver 51 of the management system 50transmits the response accepting the communication start request, to theterminal 10 aa that is the starting terminal (S45). Thetransmitter/receiver 51 of the management system 50 transmits, to theterminal 10 aa, relay device connection data to be used for connectingwith the relay device 30.

The transmitter/receiver 51 of the management system 50 transmits relayrequest information (relay start request) to the relay device 30, whichrequests for relaying of content data between the starting terminal 10aa and the counterpart terminal 10 da. The transmitter/receiver 11 ofeach of the terminal 10 aa and the terminal 10 da transmits the relaydevice connection data that is received from the management system 50,to the relay device 30 to connect to the relay device 30. The startingterminal 10 aa and the counterpart terminals 10 da each establish acontent data session “sed” with the relay device 30 (S47). Thetransmitter/receiver 11 of each of the terminal 10 aa and the terminal10 da transmits or receives image data and audio data to or from therelay device 30 through the established content data session “sed”.Accordingly, the starting terminal 10 aa and the counterpart terminal 10da can exchange image data and audio data therebetween.

FIG. 10 is a data sequence diagram illustrating operation of installingthe input image control program 1400 onto the input apparatus 40,according to an embodiment. Referring to FIG. 10, operation ofinstalling the input image control program 1400 (more specifically, thedisplay data obtainer 1451, the display data transmitter 1452, and theresolution converter 1453), onto the input apparatus 40, is describedaccording to the embodiment. As the input apparatus 40 connects with theterminal 10 aa through a communication cable, the connection detector 42of the input apparatus 40 detects connection with the terminal 10 aa(S70). In response to detection of connection, the installationdeterminer 43 a determines whether the input apparatus 40 is installedwith the input image control program 1400 to have the functions of thedisplay data obtainer 1451, the display data transmitter 1452, and theresolution converter 1452 (S71).

When it is determined that any one of the programs (or functions) of theinput image control program 1400 is not installed (“NO” at S71), themount unit 48 mounts the memory 1000 of the terminal 10 aa onto theinput apparatus 40 (S72). The program obtainer 43 b obtains any one ofthe programs of the input image control program 1400 (more specifically,the display data obtainer 1451, the display data transmitter 1452, andthe resolution converter 1453), from the memory 1000 of the terminal 10aa, and install the obtained program onto the input apparatus 40 (S73).Accordingly, the input apparatus 40 is installed with the input imagecontrol program 1400 to implement the display data obtainer 1451, thedisplay data transmitter 1452, and the resolution converter 1453.

As the input image control program 1400 is installed, thetransmitter/receiver 41 transmits a request for permitting execution ofthe input image control program 1400 (the display data obtainer 1451,the display data transmitter 1452, and the resolution converter 1453) tothe terminal 10 aa (S74). In response to acceptance of the permissionrequest from the terminal 10 aa, the input apparatus 40 executes theinput image control program 1400 (the display data obtainer 1451, thedisplay data transmitter 1452, and the resolution converter 1453).

FIG. 11 is a data sequence diagram illustrating operation of processingconversion of display data, according to an embodiment. Referring toFIG. 11, operation of processing conversion of display data, transmittedfrom the input apparatus 40 to the terminal 10, is described accordingto the embodiment.

The transmitter/receiver 41 of the input apparatus 40 transmits arequest for resolution information indicating a resolution of a displayarea for displaying the display image, to the terminal 10 aa (S91). Inthis embodiment, the resolution is not expressed in dots per inch (dpi),but expressed in number of image pixels. As the external datatransmitter/receiver 18 of the terminal 10 aa receives the request forresolution information, the layout obtainer 17 refers to the layoutmanagement table to obtain a size of the display area for displaying thedisplay image (S92). The example case where the default size (640, 480)of the display area is obtained at S92 is described below. As the sizeof the display area is received at the layout data obtainer 17, theexternal information transmitter/receiver 18 transmits resolutioninformation indicating a resolution corresponding to the obtaineddisplay area size, to the input apparatus 40 (S93). The resolutioncorresponding to the obtained display area size may be set equal to theobtained display area size (640, 480). Alternatively, the resolution maybe obtained by multiplying the display area size with a positive integerof more than one, such that the resolution can be proportional to thedisplay area size.

The transmitter/receiver 41 of the input apparatus 40 receives theresolution information transmitted from the terminal 10 aa. The memorycontrol 49 of the input apparatus 40 stores the received resolutioninformation in the memory 4000 (S94).

The display data obtainer 451 of the input apparatus 40 captures animage being displayed on the display 208 under control of the displaycontrol 47, to obtain display data (S95). The display data, when beingcaptured, has a resolution that is determined by the resolution of thedisplay 208. In one example, the display 208 has a resolution (1280,960), such that the display image has a resolution (1280, 960).

The resolution obtainer 44 accesses the display 208 to obtain aresolution of the display 208, and further obtains the resolutioninformation stored in the memory 4000 (S96). The resolution converter453 converts the obtained resolution of the display data, to aresolution indicated by the resolution information obtained from thememory 4000 (S97). For example, the resolution converter 453 convertsthe display data having the resolution (1280, 960), to the display datahaving the resolution (640, 480) as indicated by the stored resolutioninformation. In case an aspect ratio of a display image based on thedisplay data differs from an aspect ratio of a display area of theterminal 10 aa, the resolution converter 453 converts one of ahorizontal resolution and a vertical resolution of the display data tomatch the corresponding one of the horizontal resolution and thevertical resolution of the stored resolution information (640, 480).

The operation of S97 is described in detail referring to FIG. 12. FIG.12 is a flowchart illustrating operation of converting resolution ofdisplay data, according to an embodiment. In the following, the verticalresolution (the height) and the horizontal resolution (the width) of thedisplay 208 of the input apparatus 40 (that is, the resolution of thedisplay data) are referred to as H40 and W40, respectively. The verticalresolution (the height) and the horizontal resolution (the width) of thedisplay area of the terminal 10 aa are referred to as H10 and W10,respectively. The resolution converter 453 convert the display data tohave the vertical resolution H′, and the horizontal resolution W′, asdescribed below.

The resolution converter 453 determines whether H40 is equal to or lessthan H10, and W40 is equal to or less than W10 (S971). When it isdetermined that H40 is equal to or less than H10, and W40 is equal to orless than W10 (“YES” at S971), the resolution converter 453 determinesnot to perform any conversion, and the operation proceeds to S972. Insuch case, the resolution converter 453 sets the vertical resolution H′and the horizontal resolution W′ of the display data, respectively, toH40 and W40 of the display 208. That is, when the resolution of thedisplay data (depending on the display 208) is equal to or less than theresolution of the display area of the terminal 10 aa, the resolutionconverter 453 determines that no conversion is necessary, as the displayimage can be displayed on the display area without conversion.

When it is determined that H40 is greater than H10, or W40 is greaterthan W10 (“NO” at S971), the resolution converter 453 determines thatconversion is necessary, and the operation proceeds to S973. At S973,the resolution converter 453 further determines whether H10 is equal toor greater than W10.

When it is determined that H10 is equal to or greater than W10 (“YES” atS973), the operation proceeds to S974. At S974, the resolution converter453 converts the display data, such that the display data has thehorizontal resolution W′ that is equal to W10, and the verticalresolution H′ that is equal to H40*W10/W40. Here, W10/W40 is acompression ratio. The aspect ratio of the converted display data W′:H′is W10:H40*W10/W40, that is, W40:H40. As described above, thisconversion does not change the aspect ratio of the display data, butconverts the horizontal resolution of the display data to that of thedisplay area of the terminal 10.

When it is determined that W10 is greater than H10 (“NO” at S973), theoperation proceeds to S975. At S975, the resolution converter 453converts the display data, such that the display data has the horizontalresolution W′ that is equal to W40*H10/H40, and the vertical resolutionH′ that is equal to H10. Here, H10/H40 is a compression ratio. Theaspect ratio W′:H′ of the converted display data is W40*H10/H40:H40,that is, W40:H40. As described above, this conversion does not changethe aspect ratio of the display data, but converts the verticalresolution of the display data to that of the display area of theterminal 10.

As the resolution of the display data is converted at the resolutionconverter 453, at S98 of FIG. 11, the display data transmitter 452transmits the display data, which is converted, to the terminal 10 aa.In this embodiment, the display data transmitter 452 of the inputapparatus 40 may encode the display data in a predetermined encodingformat, before transmitting to the terminal 10 aa.

The external information transmitter/receiver 18 of the terminal 10 aareceives the display data transmitted from the input apparatus 40. Incase the display data is encoded, the external informationtransmitter/receiver 18 decodes the encoded display data. The displaycontrol 16 renders the received display data (S99) to obtain the displaydata having the resolution as indicated by the resolution information.The display control 16 resizes an image of the display data so as tomatch the size of a display image stored in the layout management table(FIG. 7A) (S100). The display control 16 further causes the displayimage, which is resized, to be displayed at a position as indicated bythe position information stored in the layout management table (FIG. 7A)(S101). When the display data is converted at S974 or S975 of FIG. 12,the display control 16 may cause the display image of the converteddisplay data at a center section of the display area of the terminal 10.In such case, the display area may have a blank area, for example, atupper and lower portions or right and left portions of the screen.Further, referring to the priority information stored in the layoutmanagement table (FIG. 7A), the display control 16 may cause the displayimage be superimposed on the captured image. The captured image may bean image captured at the camera 112 of the terminal 10 aa, or an imagecaptured and transmitted from the counterpart terminal 10 da through thecontent data communication session “sed”.

The transmitter/receiver 11 of the terminal 10 aa obtains the displaydata, which is the display image being displayed on the display 120, andencodes (compresses) the obtained display data in the predeterminedencoding format to generate the display data for transmission (S102).The predetermined encoding format may be any desired encoding format, aslong as it is compatible with a communication protocol of the contentdata communication session “sed”.

The transmitter/receiver 11 of the terminal 10 aa transmits, to therelay device 30, the display data that is generated at S102 fortransmission through the content data communication session “sed”(S103). The transmitter/receiver 11 of the terminal 10 aa furthertransmits, to the relay device 30, data of the captured image capturedby the camera 112 at the terminal 10 aa, and audio data that iscollected by the microphone 114 at the terminal 10 aa, for transmissionthrough the content data communication session “sed”. The relay device30 transmits the display data, the image data of the captured image, andthe audio data, which are received from the terminal 10 aa, to thecounterpart terminal 10 da through the content data communicationsession “sed” (S104). The transmitter/receiver 11 of the terminal 10 dareceives the display data, image data, and audio data from the relaydevice 30. In case the display data is encoded, the transmitter/receiver11 decodes the display data. The display control 16 of the terminal 10da controls the display 120 to display an image based on the decodeddisplay data (S105). Similarly, the display control 16 of the terminal10 da causes the display 120 to display an image of the received imagedata, such as the captured image transmitted from the terminal 10 aa.

Referring to FIG. 13, operation of changing a size of the display areafor displaying the display image is described according to anembodiment. FIG. 13 is a data sequence diagram illustrating operation ofchanging a size of the display area for displaying the display image.The operation may be performed at any desired time, for example, beforeor after displaying the display image at the terminal 10 aa.

For example, the user at the terminal 10 aa may change a size of thedisplay area of the display 120 with a pointer such as the mouse asillustrated in FIG. 7C. In response to the user operation for changingthe size of the display area, the operation input 12 of the terminal 10aa accepts a request for changing the size of the display area (S121).The following describes an example case in which the request forchanging the size of the display area, from (640, 480) to (1280, 960).

The memory control 19 of the terminal 10 aa updates the layoutmanagement table (FIG. 7A) to change the size of the display image from(640, 480) to (1280, 960) (S122).

The layout data obtainer 17 of the terminal 10 aa obtains sizeinformation indicating the updated size of the display image, which is(1280, 960), from the layout management table (S123). Further, thelayout data obtainer 17 calculates a resolution corresponding to theobtained size of the display image. The external informationtransmitter/receiver 18 transmits resolution information, whichindicates the resolution corresponding to the obtained size of thedisplay image, to the input apparatus 40 (S124). The resolutioncorresponding to the obtained size of the display image may be set equalto the obtained size (1280, 960), or to any value larger butproportional to the obtained size. That is, the resolution to betransmitted depends on the size of the display image.

The operation to be performed after transmission of the resolutioninformation to the input apparatus 40 is performed in a substantiallysimilar manner as described above referring to S94 to S105 of FIG. 11,such that its description is omitted. However, in this example, theresolution information transmitted at S124 is greater than theresolution information transmitted at S93. In such case, until theresolution of the display area (W10, H10) becomes equal to or greaterthan the resolution of the display 208 (W40, H40) (“YES” at S971), theresolution of the display image, which is transmitted from the inputapparatus 40 to the terminal 10, increases according to the useroperation. Accordingly, as the size of the display area for displayingthe display image increases in response to the user instruction, theresolution of the display image increases. This suppresses the suddenchange in image quality due to the change in display area size. Further,as described above referring to S124, the resolution informationcorresponding to the display area size selected by the user at theterminal 10 aa is transmitted to the input apparatus 40. The inputapparatus 40 generates image data having the resolution indicated by thereceived resolution information for transmission. As the display imageis converted at the input apparatus 40, the terminal 10 aa can easilydisplay the received display image on the display area of the screen.

The above-described operation of displaying the display image may beperformed in various other ways. For example, the terminal 10 aa doesnot have to have information indicating the size of the display image inthe layout management table, at the time when the request for resolutioninformation is received at S91. For example, when the request forresolution information is transmitted from the input apparatus 40 to theterminal 10 aa (S91), the input apparatus 40 may also transmitresolution information indicating the resolution of the display 208 ofthe input apparatus 40 to the terminal 10 aa. As the externalinformation transmitter/receiver 18 of the terminal 10 aa receives theresolution information, the memory control 19 stores a sizecorresponding to the resolution of the display 208 that is received fromthe input apparatus 40, in the layout management table in a field forthe display image. As the aspect ratio of the display area at theterminal 10 aa becomes equal to the aspect ratio of the display 208, thedisplay area does not have a blank space at upper and lower portions orright and left portions of the display image.

In case of receiving a request for changing a size of the display areaat S121, the operation input 12 may accept such request for changing asize of the display area such that an aspect ratio remains the same asthe aspect ratio being managed with the layout management table. Bykeeping the aspect ratio the same, even when the size of the displayarea changes, the display area does not have a blank space at upper andlower portions or right and left portions of the display image.

As described above, the terminal 10 obtains display area informationindicating a size of a display area of the display 120 for displaying adisplay image that is being generated and displayed at the inputapparatus 40. In one example, the display area information correspondsto a user operation that designates a size of the display area with, forexample, a pointer. In another example, the display area information maybe obtained from a memory.

The terminal 10 transmits, to the input apparatus 40, resolutioninformation that indicates a resolution of image data that matches thesize of the display area. Based on the resolution information, the inputapparatus 40 converts the display image having a resolution of thedisplay 208, to match the resolution of the display area of the display120 as indicated by the resolution information transmitted from theterminal 10. The terminal 10 receives the display image having theresolution as indicated by the resolution information, from the inputapparatus 40. The terminal 10 causes the display 120 to display thedisplay image on the display area.

Accordingly, even when displaying the display image that is input fromthe input apparatus 40 (such as the display image being displayed at theinput apparatus 40), in a display area of the display 120 for theterminal 10, the input apparatus 40 converts the display image to havethe resolution that matches the display area of the display 120 for theterminal 10. This enables the display image, input from the inputapparatus 40, to be appropriately displayed in the display area.

Even when a request for re-sizing the display area is received, theterminal 10 sends resolution information that is updated to reflect thechange to the input apparatus 40, to cause the input apparatus 40 tosend the display image having the resolution that matches the updatedresolution information.

Further, the terminal 10 stores in the memory 1000 the input imagecontrol program 1400, such as the resolution converter 1453 forconverting resolution of image data. The terminal 10 can provide suchprogram to any desired external apparatus to cause the externalapparatus to operate as the input apparatus 40.

In one example, the input apparatus 40 determines whether the resolutionconverter 1453 is installed onto the input apparatus 40. When it isdetermined that the resolution converter 1453 is not installed, theinput apparatus 40 requests the terminal 10 for resolution converter1453.

In alternative to converting the display image to have the resolutionthat matches the display area of the display 120 for the terminal 10,the display area of the display 120 for the terminal 10 may be adjustedto match an aspect ratio of the display 208 for the input apparatus 40.More specifically, based on information indicating an aspect ratio ofthe display image (resolution information) that is transmitted from theinput apparatus 40, the terminal 10 determines a size of the displayarea. Since the aspect ratio becomes the same between the display imageand the display area, the display image can be appropriately displayedin the display area, without any blank at upper and lower portions, orat right and left portions.

The terminal 10, when communicating with one or more counterpartcommunication terminals 10, further transmits the display image that isreceived from the input apparatus 40 to the one or more counterpartcommunication terminals 10 through the network 2.

In the communication system 1, in addition to captured images each beingcaptured at the terminal 10, the display image input from the externalinput apparatus 40 can be shared among the terminals 10.

The terminal 10, the relay device 30, the input apparatus 40, and themanagement system 50 in any one of the above-described embodiments maybe configured by a single computer or a plurality of computers to whichdivided portions (functions) are arbitrarily allocated.

In addition, a memory storing any one of the above-described controlprograms, such as a recording medium including a CD-ROM or the HD 204,may be provided in the form of a program product to users within acertain country or outside that country.

Although the IP address of each terminal 10 is managed in theabove-described embodiment, the embodiment is not limited to this case,such that a fully qualified domain name (FQDN) of each terminal 10 maybe managed instead, or any other identification information foridentifying the terminal 10 on the communication network 2. In thiscase, an IP address corresponding to an FQDN is obtained by a DomainName System (DNS) server of the related art.

In addition, although the case of a videoconference system has beendescribed as an example of the communication system 1 in theabove-described embodiment, the embodiment is not limited to this case,such that the communication system 1 may be a phone system such as an IPphone system or an Internet phone system. The communication system 1 maybe a telephone system including a mobile phone. In such case, theterminal 10 may correspond to a phone, such as the mobile phone.

That is, any display control apparatus capable of controlling display ofimage data received from the external apparatus as described above canoperate as the terminal 10 of any one of the above-describedembodiments. Examples of such display control apparatus include, but notlimited to, a smart phone, a smart watch, a mobile phone, a carnavigation terminal, a wearable computer, a monitoring camera, a digitalcamera communicable using WiFi, any communication device (a projector, agame machine), a digital signage, and industrial equipment with acommunication function. A wearable computer includes a watch and ahead-mounted display. Industrial equipment includes office equipmentsuch as a multifunction peripheral (MFP)/printer/product, medicalequipment such as an endoscope and a Computed Tomography (CT) scan, andagricultural equipment such as a cultivator.

In the above-described embodiments, the input apparatus 40 isimplemented by a general-purpose computer, however, the input apparatus40 may be implemented in various other ways. For example, any apparatusthat can be installed with the input image control program 1400 mayoperate as the input apparatus 40 such as a mobile phone, tablet,videoconference terminal, electronic whiteboard, etc.

In addition, although the case in which a videoconference is held by thecommunication system 1 has been described in the above-describedembodiment, the embodiment is not limited to this case. Thecommunication system 1 may be used in meetings, general conversationbetween family members or friends, or one-way presentation ofinformation.

The above-described embodiments are illustrative and do not limit thepresent invention. Thus, numerous additional modifications andvariations are possible in light of the above teachings. For example,elements and/or features of different illustrative embodiments may becombined with each other and/or substituted for each other within thescope of the present invention.

Any one of the above-described operations may be performed in variousother ways, for example, in an order different from the one describedabove.

Each of the functions of the described embodiments may be implemented byone or more processing circuits or circuitry. Processing circuitryincludes a programmed processor, as a processor includes circuitry. Aprocessing circuit also includes devices such as an application specificintegrated circuit (ASIC), DSP (digital signal processor), FPGA (fieldprogrammable gate array) and conventional circuit components arranged toperform the recited functions.

1. A display control apparatus comprising: circuitry to control displayof images on a first display provided for the display control apparatus,the images including a first image generated at the display controlapparatus and a second image generated at an external apparatus, and toobtain display area information indicating a size of a display area ofthe first display for displaying the second image; a transmitter totransmit, to the external apparatus, resolution information indicating aresolution of image data that matches the size of the display area ofthe first display; and a receiver to receive, from the externalapparatus, second image data having the resolution that matches the sizeof the display area of the first display, the second image data beinggenerated at the external apparatus based on the second image, whereinthe circuitry controls the first display to display the second image inthe display area based on the second image data received from theexternal apparatus.
 2. The display control apparatus of claim 1, furthercomprising: a memory to store an input image control program that, whenexecuted by a processor, causes the processor to generate the secondimage data having the resolution that matches the size of the displayarea of the first display, wherein the circuitry causes the externalapparatus to install the input image control program when connectionwith the external apparatus is detected.
 3. The display controlapparatus of claim 1, wherein the second image is being displayed on asecond display provided for the external apparatus.
 4. The displaycontrol apparatus of claim 3, wherein the size of the display area ofthe first display is determined based on an aspect ratio of the secondimage being displayed on the second display, such that the aspect ratiobecomes the same between the display area and the second image.
 5. Thedisplay control apparatus of claim 1, further comprising: a userinterface to receive a user instruction for designating the size of thedisplay area.
 6. The display control apparatus of claim 1, wherein, whenthe display control apparatus is a communication apparatus capable ofcommunicating with one or more counterpart communication apparatuses,the transmitter further transmits the second image data received fromthe external apparatus to the one or more counterpart communicationapparatuses through a network.
 7. The display control apparatus of claim6, wherein the first image is an image that is captured at the displaycontrol apparatus for transmission to the one or more counterpartcommunication apparatuses through the network.
 8. A communicationsystem, comprising: the display control apparatus of claim 1; and theexternal apparatus connectable with the display control apparatus. 9.The communication system of claim 8, wherein the external apparatusincludes: circuitry to determine whether the input image control programis installed onto the external apparatus; and a transmitter to send arequest for the input image control program to the display controlapparatus based on a determination indicating that the input imagecontrol program is not installed.
 10. A method for controlling displayof images on a first display provided for a display control apparatus,the images including a first image generated at the display controlapparatus and a second image generated at an external apparatus, themethod comprising: obtaining display area information indicating a sizeof a display area of the first display for displaying the second image;transmitting, to the external apparatus, resolution informationindicating a resolution of image data that matches the size of the display area of the first display; receiving, from the external apparatus,second image data having the resolution that matches the size of thedisplay area of the first display, the second image data being generatedat the external apparatus based on the second image; and controlling thefirst display to display the second image in the display area based onthe second image data received from the external apparatus.
 11. Themethod of claim 10, further comprising: storing, in a memory, an inputimage control program that, when executed by a processor, causes theprocessor to generate the second image data having the resolution thatmatches the size of the display area of the first display; and causingthe external apparatus to install the input image control program whenconnection between the display control apparatus and the externalapparatus is detected.
 12. The method of claim 10, wherein the secondimage is being displayed on a second display provided for the externalapparatus.
 13. The method of claim 12, further comprising: determiningthe size of the display area of the first display based on an aspectratio of the second image being displayed on the second display, causingthe aspect ratio be the same between the display area and the secondimage.
 14. The method of claim 10, further comprising: receiving a userinstruction for designating the size of the display area.
 15. The methodof claim 10, further comprising: transmitting the second image datareceived from the external apparatus to one or more counterpartcommunication apparatuses through a network, the counterpartcommunication apparatuses each communicating with the display controlapparatus.
 16. A non-transitory recording medium which, when executed byone or more processors, cause the processors to perform a method forcontrolling display of images on a first display provided for a displaycontrol apparatus, the images including a first image generated at thedisplay control apparatus and a second image generated at an externalapparatus, the method comprising: obtaining display area informationindicating a size of a display area of the first display for displayingthe second image; transmitting, to the external apparatus, resolutioninformation indicating a resolution of image data that matches the sizeof the display area of the first display; receiving, from the externalapparatus, second image data having the resolution that matches the sizeof the display area of the first display, the second image data beinggenerated at the external apparatus based on the second image; andcontrolling the first display to display the second image in the displayarea based on the second image data received from the externalapparatus.